Hi - ouch - keep flexing your toes upwards, especially before you go to bed, that'll keep the calf muscle stretched. Also, what the other ladies suggest - take extra magnesium - pregnancy depletes our normal level, plus circulation to extremeties (legs/arms) is compromised during pregnancy, hence the cramping due to less blood flow in distal muscles. I would also highly recommend putting a cupful of epsom salts in your bath at night - fabulous for the muscles, not to mention relaxing htp

Lee